1. Field of the Invention
The invention relates to display devices, and in particular to light emitting devices capable of emitting collimated and polarized lights.
2. Description of the Related Art
Light emitting devices, such as display devices, have been extensively applied in business, entertainment, military, medical, engineering, and civil regimes. With the application of display devices gradually expanding and being more popular, the development trends of the display devices are intended to become lighter, thinner, and more compact for the purpose of lower power consumption and more environmental friendliness to human beings.
Generally speaking, all of the display devices require light sources. For example, conventional projector adapts high efficient high-pressure mercury lamps (UHE) or (UHP) as light sources. Light emission of UHE or UHP, however, preferably has to be a collimated light beam, which is regulated by optical systems for the projector application. In reality, most of emitted light angles of the abovementioned lamps exceed 10 degrees, the light at these emission angles cannot be collimated completely resulting in waste of light energy. In addition, he UHE and UHP, moreover, also emits infrared light, which also can not be used in projector application and most of these infrared is transformed into heat, scattered light, and thermal noise. Therefore the more widely spread application of the projector is limited. Furthermore, for the flat panel display (FPD), lots of polarizer films and filters are required to implement in these devices. The multiple light absorption and reflection of these optical components also results in inefficient consumption of light energy for the flat panel display application.
Accordingly, light emitting devices capable of emitting collimated and polarized lights to reduce optical components are indispensable in the industry to overcome the abovementioned problems.